1. Field of the Invention
The present invention relates to a card connector, and more particularly to a card connector in which surface terminals of a card that is inserted in a normal posture into a card insertion space of a case are contacted with contacts of the case, and, when a card is inserted in a posture different from the normal posture, such erroneous insertion is blocked.
2. Explanation of Related Art
Conventionally, a technique for preventing erroneous insertion of a card from occurring in an IC card connector is known (see Japanese Patent Application Laying-Open No. 10-187896). In the technique, a metal cover of a case is provided with a stopper piece which is formed by cutting and raising, and, when a card is erroneously inserted in a posture different from the normal posture, the tip end of the stopper piece bumps against the front end face in the insertion direction of the card to block further insertion or movement of the card.
In the conventional technique, when the direction of inserting a card into the case is defined as the forward direction, the stopper piece which is formed by cutting and raising the metal cover elongates in the rearward direction, and the front end face in the insertion direction of the card which is erroneously inserted bumps against the tip end of the thus configured stopper piece, thereby blocking erroneous insertion. When such an IC card connector is miniaturized, the metal cover must be thinned, and hence also the stopper piece which is formed by cutting and raising the metal cover is inevitably thinned. When the front end face in the insertion direction of the card which is erroneously inserted bumps against the tip end of the stopper piece, therefore, the stopper piece may buckle or deform.
To comply with this, a technique has been proposed (see Japanese Patent Application Laying-Open No. 2003-31286 or No. 2003-59588). In the proposed technique, a flat tongue-like locking projection in a cut and raised state is bendingly formed in a cover of a case. The locking projection is engaged with the front end face in the insertion direction of a card which is erroneously inserted in a posture different from a normal posture, thereby blocking further insertion or movement of the card. Moreover, the bend line of a basal portion of the locking projection elongates in the card insertion direction, and the rear end face in the plate surface width direction of the locking projection is formed as a locking portion for the front end face in the insertion direction of a card.
According to the configuration, when the locking portion is engaged with the front end face in the insertion direction of a card which is erroneously inserted, the pushing force applied on the card acts in the plate surface width direction of the locking projection. As compared with the stopper piece disclosed in Japanese Patent Application Laying-Open No. 10-187896, therefore, the locking projection is provided with a larger strength against erroneous card insertion, so that the locking projection is correspondingly prevented from buckling or deforming.
Recently, miniaturization of a card is remarkably advanced, and a cover of a case is thinned in accordance with the miniaturization. Therefore, it is requested to take measures for improving the mechanical structural strength on such a locking projection for blocking insertion or movement of an erroneously inserted card. When a card is to be inserted into a case, conventionally, the card is pushed with one hand. By contrast, a case where a card is pushed with both hands while applying a force which is larger than that applied in the conventional case may occur.
Under such a situation, when measures for preventing erroneous card insertion from occurring are taken by employing the stopper piece disclosed in Japanese Patent Application Laying-Open No. 10-187896, there arises the possibility that the stopper piece buckles or deforms, and moreover an erroneously inserted card enters under the buckling or deforming stopper piece, whereby the card or a connector is damaged or broken.
By contrast, when measures for preventing erroneous card insertion from occurring are taken by employing the locking projection disclosed in Japanese Patent Application Laying-Open Nos. 2003-31286 and 2003-59588, the strength against erroneous card insertion is enhanced as compared with the case of the stopper piece disclosed in Japanese Patent Application Laying-Open No. 10-187896, and hence the locking projection hardly buckles or deforms. When a large pushing force which exceeds a certain level is applied to an erroneously inserted card, however, there is the possibility that the locking projection cannot withstand the pushing force to buckle or deform. In the card connectors of Japanese Patent Application Laying-Open Nos. 2003-31286 and 2003-59588, therefore, the locking projection in a cut and raised state is bendingly formed in plural positions of the cover so that the locking projections are laterally arranged. According to the configuration, however, one or more of the locking projections are inevitably positioned in a region where a terminal formed region of a card which is inserted and moved in a normal posture passes, and hence there is the possibility that, during the process of inserting the card, the locking projections damage terminals of the card or the locking projections and the terminals are short-circuited. In order to prevent such a situation from occurring, in the card connector disclosed in Japanese Patent Application Laying-Open No. 2003-31286, additional measures that the locking projections are covered by an electrically insulative resin are taken.
In the case where erroneous card insertion is prevented from occurring by the locking projections disclosed in Japanese Patent Application Laying-Open Nos. 2003-31286 and 2003-59588, when a large pushing force which exceeds a certain level is applied to an erroneously inserted card, the locking portions of the end faces of the locking projections may slip with respect to the front end face in the insertion direction of the card. When such slippage occurs, there may arise a situation where the locking projections are raised while causing the cover to upward deform, and the card enters under the locking projections. When the card enters under the locking projections, the cover excessively swells and deforms, thereby causing a problem in that the connector may be broken.